With the rapid development of the Internet, various types of data explosively grow. Because of the characteristics such as decentralization, non-tampering, and transparency, the blockchain currently becomes a major focus and research direction in many technical fields.
In the current blockchain technology, blockchain data is mainly updated based on transactions, for example, digest information of transactions within a time period is formed, and the digest information is stored together with a digest in the previous blockchain to form a new block. In blockchain applications, both parties can agree on contract content or contract execution offline, and then store related data in the blockchain. In an on-chain process (a process of storing data in the blockchain), a contract can be encrypted by using some encryption methods, to protect the contract content and prevent generation of an illegal contract or an illegal modification to the contract. However, key information of contract participants may be maliciously stolen and lost in some application scenarios. Consequently, a relatively high data security risk can be generated for the blockchain, security trust of blockchain users for provided blockchain services can be reduced, and user experience is also reduced.
Therefore, there is an urgent need for a solution that can more effectively improve data security in blockchain data services.